Nirvana fallacy?

In 2011, we had a referendum in the UK on whether to switch to preferential voting (which was called the 'Alternative Vote') instead of the First Past The Post system we use at the moment. In other words, instead of just putting a cross next to their preferred candidate, voters would rank the candidates in order of preference, by putting a 1 next to their first choice, a 2 next to their second and so on - they could even just put a 1 next to their preference and leave it at that if they didn't care about any of the others.

As it turned out, 67% voted against the new system, but many of those that did have claimed that they only did so because it wasn't the system they wanted, which was Proportional Representation. Would that be a Nirvana Fallacy? Because I'm inclined to think that although AV might not have been the system that most people wanted, it was the only one that the Government were prepared to offer, so if people didn't like FPTP then they should've just voted for what was going - if nothing else, it would've eliminated the perceived need for tactical voting (where people vote for the candidate that's most likely to beat the one they don't want instead of for the one they do want), because voters could put their ideal choice first and their current tactical one second, thus giving a truer reflection of their preferences.

Some people have cynically claimed that the Government deliberately offered a system that they knew most people didn't want so they could use the inevitable rejection of it as 'proof' that the public were happy with the current one. Is there any fallacy there? (Personally, I would've thought that if that was the case then it only proves my point further - that people should've voted for what was on offer if they didn't like the current system!)

I remember the AV Referendum in 2011. I don't think voting against AV constituted a Nirvana Fallacy.

The Fallacy is comitted when a solution is rejected because it is not perfect, where a perfect solution is not possible or realistic. No voting system is perfect - thus, if one is to be replaced by another, the replacement needs to be worth the hassle of introducing it.

It seems that most British voters at the time did not see AV as having passed the cost-benefit test, as in, it did not bring enough benefits over FPTP to be worth replacing it with (whereas PR does). Especially given that if AV had been adopted, it might make it harder to campaign for PR in the future.

You make a good point though and I even begin to doubt my response. I wonder what others think.

For the nirvana fallacy to be in play, we'd need to be in a situation where a (potentially) acceptable solution was rejected because it wasn't perfect.  Perhaps that's what some folks meant by "not the system they wanted", but that wording makes me think they had in mind a different system that wasn't on the ballot.

Could this situation be more of a false dilemma ?  

Bias is something we all fight when addressing any issue. As Michael Shermer put it, people believe things because they want to. When you say, "Some people have cynically claimed.." you have injected your bias with the word "cynically."